Improve measurements

[ErikKalkoken]

• Measure throughput against aiosqlite instead of classic DBM

[codecov]

Codecov Report

Merging #4 (1a9ab62) into main (c50f53a) will not change coverage.
The diff coverage is 100.00%.

❗ Current head 1a9ab62 differs from pull request most recent head 80bc5c0. Consider uploading reports for the commit 80bc5c0 to get more accurate results

@@           Coverage Diff           @@
##             main       #4   +/-   ##
=======================================
  Coverage   95.67%   95.67%           
=======================================
  Files           3        3           
  Lines         162      162           
  Branches       17       17           
=======================================
  Hits          155      155           
  Misses          4        4           
  Partials        3        3           

Impacted Files	Coverage Δ
src/aiodbm/core.py	95.09% <ø> (ø)
src/aiodbm/__init__.py	100.00% <100.00%> (ø)